November 2007

 My horse was recently diagnosed with an allergy to hay. What other options are available?

A With the current drought taking a heavy toll on the Maryland hay industry, even those without horses allerigic to hay may be looking for good hay alternatives. There are several options that you should consider when feeding a horse with an allergy to hay. The first option is to continue to feed hay, but you would need to change the type and/or the way it is fed. Changing to a high quality grass, mixed, or alfalfa hay that’s not dry, dusty, overly mature, or contaminated with mold may be beneficial to your horse. Many hays that look visually free of mold actually carry mold spores that, over time, contribute to causing a hay allergy. High quality hays that are cut and baled at the right time and are usually green, leafy, soft to the touch, and free of dust are ideal to feed to horses. Keep in mind that some allergies to hay only develop when a horse is fed a certain species of hay (e.g. Timothy, Orchardgrass, Alfalfa), but they are fine when they are fed a different species of hay.

Another option is take high quality hay and soak it in water for 10 minutes just before feeding. Soaking helps to reduce the dust associated with feeding hay. However, soaking won’t eliminate mold spores, so it’s important to feed quality hay that’s free of potential molds.

Feeding hay cubes or pellets that are commercially available and generally lower in dust and fine particles is another option. Processed hay cubes and pellets are made from coarsely chopped dry hay that is compressed into a cube or pellet shape. Alfalfa is usually the species of choice to use in hay cubes because it sticks together better than grasses. Play close attention to the nutrient content stated on the alfalfa cube or pellet bag because you’re likely feeding a diet that’s higher in protein, vitamin, and mineral content than before. If you were also adding grain or supplements to the horse’s diet, the amount of those that you feed along with alfalfa cubes may need to be reduced. Hay cubes and pellets can also be soaked for 10 minutes prior to feeding time.

Many horses with allergies to hay do quite well when they are turned out on pasture. Pasture has a high water content and it is unlikely to be moldy like hay. Keep in mind that if a horse has an allergy to a certain hay species, they are likely to have an allergy to the same species in the pasture. Also, some horses develop multiple allergies and can become allergic to pollen in the grasses and in the trees surrounding the pasture. In those extreme cases, horses have to be housed on dry lots and fed forage alternatives.

If changing the type and manner that hay is fed to your horse doesn’t improve his condition within one week, your horse is likely a candidate for a hay substitute. Feeding shredded beet pulp to a horse with hay allergies is common. Beet pulp is a by-product of sugar beet processing and it contains about 10% protein and 18% fiber. The advantages of feeding beet pulp are that few horses have developed allergies to it, it’s easy to purchase, handle, and store, relatively inexpensive, easy to soak and feed, and highly palatable and digestible. Soaking of beet pulp 1- 2 hours before is suggested, however, several studies have found that feeding horses up to 45% of their daily diet as dried beet pulp has not been found to cause any adverse effects in horses. Some of the disadvantages of feeding beet pulp are that it’s not an equal substitute to hay in that is contains lower quantities of vitamins and minerals. Therefore, a vitamin and mineral supplement may be offered when feeding a diet that contains a significant amount of beep pulp.

You could also contact several local feed companies and ask them if they have commercially available products that have been specifically formulated for horses with allergies. Some companies have a “complete” feed that has a high fiber content along with providing other important nutrients like carbohydrates, protein, vitamins, and minerals. Many of those complete feeds include beet pulp to contribute to the fiber component.

There are many options for feeding a horse with a hay allergy. When you make a change to the diet to see if it helps reduce the allergic condition, try out one change at a time and try to wait a week to see if it helps. If you try too many changes at once, you may not be able to figure out what works for your horse.

Dr. Amy Burk – University of Maryland


This column is sponsored by the University of Maryland. The views expressed herein are those of the author and are not necessarily those of The Equiery’s publisher or staff. If you have a question for our Maryland Experts, you can e-mail it to either Dr. Amy Burk at or Erin Petersen at If they can not answer your question directly, they will find the expert who can!